Review on Usmile XSU220 - 220mm Carbon Fiber Quadcopter Frame for FPV Drone Racing and Freestyle - Enhanced Performance Similar to QAV210, QAV250, QAV-R, QAV-X, Martian II, RX220 by Amanda Smith

Modern 30.5 x 30.5 stacks are very difficult to fit into this frame. The standoffs are very tight to the board. I also had to throw away the carbon sheets for the camera because they don't fit very well. I used a metal Runcam mounting bracket with a nut and bolt combination through one of the holes in the base plate. Like a glove. It should work like a good killer.